Lesson 2

Marshmallows and Containers

Est. Class Sessions: 2–3

Developing the Lesson

Part 1: Introduce the Lab

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Volume is the measure of the space occupied by, or the space inside, an object. When the volume of the inside of an object is measured, it is sometimes referred to as the object's capacity. For the purposes of this lab, use the term volume to refer to the capacity of the containers. An important idea of this lab is that examining a single dimension of a container (e.g., height only) will not yield an accurate picture of its volume.

Introduce Volume. Display containers of different shapes and the miniature marshmallows or beans you plan to use for the lab.

Ask:

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  • Which container do you think will hold the most marshmallows? [Record students' predictions on chart paper.] Why do you think so?
  • What could you do to find out which container holds the most marshmallows?

If students suggest filling the containers with marshmallows, allow volunteers to place marshmallows, five or ten at a time, into each container. This will reinforce skip counting.

Introduce the term volume:

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  • Volume is a measure of the amount of space an object occupies or the amount of space inside a container.
  • How could you find out which container has the greatest volume? (Possible response: Fill the containers with marshmallows and find out which container holds the most.)
  • Which container do you think will have the greatest volume? Why?

Hold up your referent bags of marshmallows.

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  • How many marshmallows will fill the tall container? More than 50? More than 10? More than 100? Why do you think so?

Record students' predictions on chart paper. Ask students to record their estimate in Question 1 of the Marshmallows and Containers pages in the Student Activity Book as well. Explain that they will test their predictions during the lab.

Demonstrate Lab Procedure. Tell students they will use the TIMS Laboratory Method to complete this investigation. Before students begin, demonstrate and discuss the lab procedure.

Show students the miniature marshmallows and a set of three containers. Have students name each container for easy identification. For example, the names can be the actual names of the containers, such as the graduated cylinder, margarine tub, and ice cream lid. Students can name them cylinder, tub, and lid. Do not use labels like "biggest", "middle", and "smallest" because they imply volume or height and are misleading.

Discuss the variables that will be studied: the type of container (cylinder, tub, lid) and the number of marshmallows.

Discuss filling the containers. Demonstrate stuffing marshmallows into one container and dropping them into another. Ask students how they can fill the containers so that everyone fills all three of their containers the same way, so that the investigation is "fair." The marshmallows should be dropped in—not stuffed—so that the number of marshmallows will be the same no matter who fills the same size container.

Ask:

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  • How can you accurately and efficiently count the marshmallows in each container? (We could group and count them.)

Draw Pictures. Ask students to draw pictures of the investigation using your demonstration as a guide. Although students will work in pairs, each student should draw a picture of the lab for Question 2 on the Marshmallows and Containers pages in the Student Activity Book. An example of student work is shown in Figure 1.

Identify the important lab elements when viewing student pictures. The pictures should identify the two main variables and show the procedure in some way so that another person can see how to do the lab.

Adventure Book:
Student Activity Book: 227
Answers
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SG_Mini
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Master:
Sample student drawing of investigation
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